You can't really judge gamepass until a few years down the line and Microsoft have delivered their big new IPs on it. Right now it's still fledgling but already has a lot of worth and some of that is obviously based on their support of BC.
The danger is if it leads to market fragmentation and we end up with EA Play, GPU, Ubisoft+, SQEnix forever, Rockstar etc. then it becomes very difficult to see how anyone can afford all games. Having said that as long as the original purchase model is preserves (buy a single game at retail), then it's just a service that will appeal to a lot of people.
If Sony started Sony Play for £15 a month and you got Miles Morales, Ratchet and Clank, GT7, Horizon: Forbidden West, Demon's Souls on day one without needing to drop £70, as well as access to all their 1st party previous titles that would also be a great deal (with a lot of filler). The only thing gamepass is missing at the moment is the big first party IPs. Whether they deliver or not is another thing but they are on the way. GPU also ensures that there is longevity in its titles as well. At any one time you have 15 million people with access to an online mode. Without people needing to buy the game -we see what that does for games like Among Us, Fall Guys and Secret Neighbor.
But players still have the option to just purchase what they want when they want. No one is obliged to take GPU, they can still buy Cyberpunk at release, they can still buy Destiny 2 and Call of Duty and play them as normal. They can also do that with Halo Infinite. I really dont get the obsession with gamepass - there have been like 6 threads on it in the last 3 days or something.